水驱油藏分层注水效率评价新方法

A new method to evaluate the injection efficiency of different layers in waterflooding reservoir

分层注水效率评价是确定油藏合理注采制度的重要依据。针对传统油藏工程方法无法考虑生产动态特征、数值模拟方法计算效率低等问题,基于油藏模拟连通(inter-connection based numeric simulation,INSIM)网络模型建立了一套水驱油藏分层注水效率评价新方法。该方法不需要复杂地质建模,而是通过拟合生产动态获取井间连通参数来计算单井分层注水劈分系数和注水效率,识别注采关系、注水受效状况。算例结果表明,该方法求得的注水井平面劈分与流线模拟结果基本一致,同时计算速度可提高几十倍,对新疆油田W30油藏进行注水效率评价和生产制度优化后取得了明显的增油降水效果。

It is an important basis to comfirm the reasonable injection and production rate that the evaluation of multi-layer reservoir water injection efficiency is.Base on the inter-connection based numeric simulation(INSIM)model,a connected network model and a new method was built up to evaluate the injection efficiency of different layers in water flooding reservoir.Without modeling a complicated geological structure model,the interaction of interwells such as injetion-production correlation and water injection efficiency could be revealed by simulating the production performance and computing the layer dividing coefficient and well dividing coefficient.A numerical example was used to show the result consistency of this method,and the frontsim and the calculation speed of this method was several dozen times faster than the numerical simulation.An adjusted production plan,which was formulated base on this method,had been applicated to guide the fast production optimization in Xinjiang oil field W30 reservoir,the water injection rate of multi-layer reservoirs could be optimised subtly by the injection efficiency of different layer.